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Diesel vs Hybrid

I remember you asking - will the future cars be powered by diesel or hybrid? Apparently the Germans say hybrid!

GERMANY: Diesel share has peaked – study

19 May 2008 | Source: editorial team

A new study has found that the diesel share of the German car market has peaked and that it will start falling from around 48% today to 30% by 2020.

The study by the Centre Automotive Research (CAR) at the college of Gelsenkirchen, and headed by Ferdinand Dudenhöffer, cites seven reasons for the future fall in diesel share which it says will be damaging to the competitiveness of the German automotive industry, which is a world leader in diesel technology.

The study, reported by Automobilwoche, said the main reason for the end of the diesel boom is the improved efficiency of petrol cars, downsizing, second generation technology and double turbocharging.

In addition the price differential between diesel and petrol is falling.

The third reason is falling values of used diesel cars. CAR attributes this partly to the fact that private used car buyers generally drive fewer kilometres than new car owners and this, combined with the reduced price advantage, means that diesel no longer adds up as an alternative.

Company car buyers are also turning away from diesels, partly because price rises for diesel cars have been higher recently, as new technology such as Bluetec (Mercedes) and BlueMotion (VW group) has been added to newly-launched models.

From 2010 all diesel cars will be required to have NOx filters, which will add further cost. These filters will require servicing, too, leading to even more cost for owners.

Petrol hybrids will put the final nail in the coffin for diesels. Hybrid technology will be enough to give petrol a firm CO2 emissions advantage over diesel.

For 2015 CAR is forecasting a 38% share in diesel, falling to 30% by 2020.


Derek Holder



"To use the medical term incorrectly (but in its most widely understood meaning), you want a schizophrenic car."

Thanks for acknowledging that you've used the term incorrectly, but you're still a mile off the mark. Dissociative Identity Disorder is what you mean. ( Schizophrenia has nothing to do with this, and its "most widely understood meaning" is typically wrong.

You are usually an excellent myth buster, so please don't be so sloppy in helping to perpetuate this one.

Matt King


What Cars?

Re "performance and economy" great article, but please name these vehicles! Also be interesting to include price and safety to the selection criteria.

Derek Holder


The criteria mentioned in the article are pretty explicit: turbocharged, about 2 litres, four cylinder, 1300 – 1500kg.

Forgotten Daihatsu

Performance with Economy - Thankyou for this article, very interesting. Just wanted to let you know that I've recently found my perfect all-round vehicle with a bit of performance and excellent economy, a 2004 Daihatsu Sirion GTVi (actually I see you've recommended it in one of your past articles).

My real-world fuel consumption since I've had the car (only 3 months or so) has been a rock solid 5.5 litres / 100 km average. And I definitely don't drive like a granny, I haven't lost a traffic light grand prix yet, and really enjoy hooning round some favourite corners (although the suspension could use a little tweaking).

Plus it seats 5 and has a decent boot (beats my MR2 there) and never breaks down (beats my Alfa 33 there). And it's so much fun to drive! I think this is the car I should have bought a long time ago.

John Williams


Pre-Warming Engine

We all know that fuel consumption is much higher when an engine is cold at startup. Has anyone experimented with fitting a engine sump heater (as fitted in cold climates) to see if it can improve start up emissions and economy in warmer climates? Maybe a few cents of electricity per day could save us lots of petrol.



Sounds like the idea has merit to us. Anyone tried it?


i was looking into intercooler efficiency and ways of making an efficient turbo project without shelling out top dollars when a friend of mine sent me the intercooler flows link. i must say this site rocks! one of the best ive come across and i like how it has alot of DIY articles. im still reading, thanks.

Caude B


Fixing Thermocouple

I love your website. Its so helpfull and unique in the way that if offers so much info to a buddying autmotive enthusiast. I was just enquiring about Issue 56 TempScreen: Part 1 – Installing the Intake Air Temp Probe. I was wondering, how is the Thermocouple Probe secured to the unit to stop it simply sliding out ?? I am running a high boost set-up and am worried about the boost pressures simply blowing out the Thermocouple probe OR it simply vibrating out. Is the Thermocouple probe crimped into the cable gland or is it attached using adhesive or possibly soldered?? What is stopping it from simply falling out ?? Thanks heaps for the info, Keep the Autospeed editions coming :)



The thermocouple is normally a tight fit in the olive. If it isn’t, a gentle crimp could be used.

Economical Superchargers

hi just a few comments on your article "performance with economy" A supercharged car should be better on fuel than a turbo when driving for economy if the charger is clutched as the exhaust will flow better. If possible an article on how camshaft profile will effect fuel consumption would be good I know for example if the inlet valve is shut latter that you will improve top end power and fuel consumption at cruse at the cost of bottom end toque due to reduced pumping losses great magazine

Michael Caldwell



Regarding your article "Exhausted performance" I find it interesting that the properly built system has such small gains compared to the poorly built system. Being an engineer with an automotive company, I would've found it interesting to have seen a dyno test with an OE exhaust. Your article didn't compare the good system to the OE system. It only compared it to the bad system. Because of this, I have some very appropriate criticism, and a few words of wisdom to give.

No doubt, the low-end performance (where airflow isn't at its highest) of the properly built system brought the car back to OE performance levels. However, what of the high-end performance? Was it better than the stock exhaust? The article stated how bad the poorly made"performance" exhaust was made, but the gains compared to the "properly made" exhaust weren't exactly astronomical. You can't say that the previous "high performance" exhaust was so bad, then say it was a "high performance" exhaust - it was a low performance exhaust, made by people who didn't know what they were doing, and it performed poorly compared to the OE exhaust - your article stated this, so don't say at end that it was "high performance" (trying to say that it was somehow better than the OE system), because it wasn't. Don't contradict yourself. Before you say that the high-end was better with the old "performance exhaust" than the OE exhaust, take a look at the quality of each... If the old "high performance" exhaust is bad enough to create a flow restriction at low RPM, then it's certain to create enough restriction to degrade high-end performance.

Considering how poorly made the first modified exhaust was, there's no doubt that the car was robbed of power, compared to the factory exhaust. Did the new exhaust increase the power compared to the OE exhaust? Did it even get to the same power level as the OE exhaust? I know of a case where someone spent a large amount of money on a "properly made" aftermarket "performance" exhaust system, and it resulted in a loss of power and torque, compared the the OE exhaust system. The car's owner eventually returned the car to standard, and told the automotive company's field service engineer "hats off to your exhaust guys. I don't know how they did it, but they got more power out of the car than I could."

The car companies and their suppliers have MUCH more sophisticated design tools available to them than even the very best exhaust shop. They're able to model VERY complicated flow scenario's for the entire load and rev range. Because of this, they're able to design exhaust systems that are efficient (ie: don't rob the engine of power, but help it to achieve the maximum power possible), while being MUCH more quiet than aftermarket exhausts. Many thousands of dollars are spent by the auto companies and their exhaust suppliers to ensure that there are no annoying booms (or if they're unavoidable, to ensure that the booms are minimised), while maximum performance, and legal exhaust gas and noise emission levels are achieved. Anyone who thinks that they're doing themselves a service by modifying their modern car's exhaust is decieved, unless they've first made enough modifications to increase airflow through the engine by enough to make the OE exhaust restrictive.

In effect, all your article showed was how people who don't know what they're doing can't get it right.



We’ve done plenty of articles in the past comparing aftermarket to OE exhausts. In nearly all cases, the aftermarket exhaust allows the engine to develop more power. With appropriate tuning of the engine management, that’s the outcome in every car we’ve ever seen modified.

The article that you’re commenting on compared the performance of two aftermarket exhausts, something that is done rarely. The article showed a clear and major performance difference between the two exhausts.

Your comments about the effectiveness of OE exhausts sound great – until you actually go and look at lots of standard factory exhausts. We’ve seen plenty of factory exhaust systems of very poor design for performance, including crimped pipes to clear suspension members, very restrictive mufflers, and terribly flowing exhaust manifolds. We’ve also been in completely standard cars that had audible exhaust resonances.

It remains the case that in most cars, improving the flow of the exhaust is one of the first and simplest steps to improving power.

Finally, your comment “In effect, all your article showed was how people who don't know what they're doing can't get it right” is exactly the point of the story. And what a good story it was to show that!

New Car Reviews

Where are your new car reviews? Aren't you doing them any more? I'm crushed. All the tech articles are interesting but i live for your new car reviews.



For reasons that have been canvassed many times here before, we’re now not actively chasing new cars to review.

Plastic Undertray

In issue 322 Modifying Under-Car Airflow, Part 2, you mention buying ABS plastic to make the front under body aerodynamic tray. Can you tell me which plastic supplier you used please?

David Hardwick


Easiest is to do a Yellow Pages search under ‘Industrial Plastics Suppliers’ or something similar.

Home Dyno

In a recent article you gave a link to "The Home Dyno" but I could not get the link to work- "Access Denied" I have done various searches but cannot find The Home Dyno. I am very interested in obtaining this software as it will help me ommensely with my tuning and performance investigation activities on predominently my Subarus. Can you please give me contact information. Thanks for a really interesting web publication which I look forward to everytime I see it on my screen.

Harvey Smith

United Kingdom

We also can’t find the link any more. However, we’d suggest that using a stopwatch and some empty road, or a simple accelerometer, will give more useful results.

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